The product cut by the invention is usually continuous and, many times, interfolded as provided in co-owned U.S. Pat. No. 4,052,048. Exemplary of the apparatus used to cut the ribbon into stacks is co-owned U.S. Pat. No. 3,288,009. More generally, over the last 30 years the primary method of conveying a ribbon through a saw has been with the use of flight bars mounted on a chain both above and below the ribbon. At times on slow machines only a bottom flighted conveyor was used and the top of the ribbon was held down with plates spaced on each side of the saw blades and traveling with the reciprocating motion saws.
A commercial machine embodying the above principle incorporated flights that were spaced to generate a repeating pattern of openings for the blade to pass through, equal to the cutoff length that was desired. When other cutoffs were required the bars were manually respaced or the entire chain assembly replaced. This system has worked well and has no known speed limitations other than the saw.
While this system has worked well for machines whose cutoff length is dedicated to a single size for long periods of time, production needs now increasingly vary and the cutoff length requirements can often change on a daily basis. The current flight conveyor requires a minimum of 4 hours to replace chains in order to achieve a new repeat and this is generally unacceptable.
The object of the instant invention is to retain the benefits of flighted cutting while obtaining quick length adjustability.